JPS62285871A - Sheet oblique travel correction device - Google Patents

Abstract

PURPOSE:To improve space efficiency and to make cost reduction, by correcting an oblique travel of a sheet by changing and releasing transportation force of a variable transportation means, and more specifically by operating pressing contact force of a pair of rotary members. CONSTITUTION:A pair of rotary members 13, 14 continue their rotation even after a sheet member transported to a transportation passage 12 by the rotary members 13, 14 strikes against a stopper. However, since pressing contact force of a pressing roller 14 is weak, the sheet forms a loop at an opening 23 and stays keeping a prescribed amount of the loop according to a deflection of a Mylar film 19. When the roller 14 is separated from the transportation roller 13, the sheet member dissolves the loop for extension because of its firmness and spring back force of the Myler film 19, which absorbs an remarkable oblique travel of the sheet so that it stays in the transportation passage without making deflection from its front end to its back end. Next, strong pressing contact force is applied to the roller 14 in succession to the weak pressing contact force and a pair of folding rollers 29, 30 form a folding to the sheet. When the sheet strikes against a stopper 35, it is folded to a Z-shape by folding rollers 30, 31.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention provides a skew correction device for correcting skew of a sheet material in a sheet folding device that performs folding processing on a conveyed sheet material. It is related to.

(Prior Art and Problems) Conventionally, this type of device has a pair of register rollers disposed in the sheet conveyance path in order to align the sheet material in the traveling direction, that is, correct the skew. The registration roller pair is brought into contact with the nip portion, synchronized, and then the registration roller pair is activated to correct the skew of the sheet material. In order to complete the ON-OFF control, the rotation/stop configuration of the register rollers, etc., the configuration was not necessarily satisfactory in terms of space efficiency and cost factors.

[Configuration to solve problems]

The present invention has been made to solve the problems of the prior art described above, and has the following configuration. That is, a pair of folding rollers that pinch and crease the sheet material, a conveyance path having an opening at the portion of the pair of folding rollers, and a released state in which the sheet material is not restrained and is located upstream of the pair of folding rollers on the conveyance path.
A variable conveyance means that can take a weak conveyance state in which a weak force is applied to the sheet material and a strong conveyance state in which a strong force is applied to the sheet material, and a stopper portion located downstream of the pair of folding rollers on the conveyance path. A sheet skew correction device is characterized in that it has the following.

(Embodiment) The present invention will be described in detail using a sheet folding device that is connected to a sheet material discharging section of an image forming apparatus main body and performs sheet folding processing as an embodiment.

The sheet material discharged from the discharge roller 2.3 of the main body of the image forming apparatus reaches the artificial roller pair 5.6 of the sheet folding device 40 incorporating the skew correction device in this embodiment, and the folding mode of the sheet material is selected. When not in use, the sheet material conveyance path switching member 7 (hereinafter simply referred to as a deflector)
The sheet, which is located in a substantially horizontal state and has passed through the pair of entrance rollers 5.6 and the deflector 7, is discharged to the paper discharge tray 11 via the through bus 8 and the pair of paper discharge rollers 9 and 10.

Next, a case in which the sheet material is Z-folded using the sheet folding device 4 will be described. When the folding mode is selected, the deflector 7 is displaced to the state shown in FIG. Then, the sheet material discharged by the discharge rollers 2 and 3 of the image forming apparatus main body is transferred to the artificial roller pair 5.6 of the sheet folding device 4.
It then passes through the deflector 7 and enters the first conveyance path 12 side. 32 is a transmission type sensor that detects passage of paper. 13
is a conveyance roller, which is driven by a drive system (not shown) and rotates in the direction of the arrow to convey the sheet material. 14 is
These pressure rollers are set at two locations in the width direction (one side is shown in FIG. 3), and are usually weak against the conveyance roller 13 by tension springs 104 as shown in FIG. 2(a). Pressed together by force. In this embodiment, the contact force is 35 g on each side, for a total of 70 g. The variable conveyance means consisting of the conveyance roller 13 and the pressure roller 14 can not only press against each other with the above-mentioned weak force, but also press strongly against each other as described below, and can also be separated from each other.

The sheet material conveyed to the first conveyance path 12 by the rotating body pair 13 and 14 continues to be conveyed until its leading end abuts against the stopper 18 . Even after the leading edge of the sheet material hits the stopper 18, the pair of rotating bodies 13 and 14 continue to rotate, but with this weak conveyance force, the sheet material forms a loop at the opening 23 of the first conveyance path 12, but the mylar film 19
It stays in a state where a certain amount of loop is maintained depending on the deflection. The state is shown in FIG. 4<8).

Next, the pressure release solenoid 20 is activated, and the release arm 21
When the roller arm 22 rotates around the fulcrum 21a, the pressurizing roller arm 22
rotates in the direction of arrow X about the support shaft 26, and transport roller 1
Stay away from 3. At this time, due to the weak conveying force up to now, 2
The loop of the sheet material S as shown in FIG. 4(a), which was formed in accordance with the deflection of the Mylar 19 in the third part, is due to the stiffness of the sheet material and the springback force of the Mylar 19.

That is, FIG. 4(b). This series of operations results in a significant skew (experimentally, 10 to 15 m+ in the feed direction).
(approximately 100 mm) is completely absorbed, the leading end of the sheet contacts the stopper 18, and the sheet remains in the first conveyance path 12 without deflection from the leading end to the trailing end.

Furthermore, after this pressure is released, the pressure release solenoid 20 is turned off.
When F is applied, the state of weak conveyance is again formed, and a loop is formed along the mylar 19 as shown in FIG.
6 in the Y direction. Then, the presser of the one end 27a of the pressure torsion coil spring 27 retreats, and the end 27a of the pressure torsion coil spring 27 comes into contact with the one end 22a of the pressure roller arm 22 and is biased, as shown in FIG. 2(b). do.

As a result, the pressing force of the pressure roller 14 on the conveying roller 14 is reduced from 35 g on one side during weak conveyance, a total of 70 g, to 300 to 50 g on one side.
00g, totaling 600 to 1000g, resulting in a strong conveyance state. Then, according to 19, the loop that was formed is
The product grows due to this strong conveyance force, is caught in the nip portion of the pair of folding rollers 29 and 30 as shown in FIG. 4(d), and a first fold is formed. transported. Then, when the leading edge of the sheet again hits the second stopper 35 and a loop is formed, the second fold of the Z-fold is formed by the pair of folding rollers 30, 31, and the Z-fold is completed. This folded sheet is the third
After passing through the 111i1 feeding path 36 and the paper ejection roller pair 9.10,
The paper is discharged onto the paper discharge tray 11.

The skew correction device of the present invention has been described above using one embodiment. Here, as a modified example, folding roller pair 29.3
It is also possible to omit the Mylar film 19 near the nip. The key to this mylar film 19 is the rotating body pair 13, which is a variable conveyance means.
．． This is because it is determined by the relative relationship between the conveying force of No. 14 and the stiffness, that is, the stiffness of the sheet material being conveyed. Therefore, when the Mylar film 19 is not provided, the pressure contact force between the conveyance roller 13 and the pressure roller 14 in the weak conveyance state and the strong conveyance state may be set to be smaller than the value in this embodiment.

Furthermore, although the variable conveyance means in this embodiment was shifted in the order of weak conveyance state, released state, weak conveyance state, and strong conveyance state, no inconvenience will occur even if the variable conveyance means is shifted directly from the released state to the strong conveyance state. .

(Effects of the Invention) As described above, the skew correction device according to the present invention uses a clutch mechanism to turn on and off the rotation of the pair of registration rollers.
1. Also, there is no need to provide a space for the sheet material to form a loop in front of the pair of registration rollers. The skew of the sheet material is corrected by changing and canceling the conveying force of the variable conveying means, that is, by manipulating the pressing force of the pair of rotating bodies in this embodiment.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sheet folding device using an embodiment of the sheet material skew correction device of the present invention, FIG. 2(a) is a side view showing the pressure mechanism of the variable conveying means, b) is a side view of the main part of the variable conveyance means, FIG. 3 is a plan view of the vicinity of the pressure roller, and FIGS. 4(a) to 4(d) are operation explanatory diagrams showing the movement of the sheet material. 4-sheet folding device, 7-deflector, 12-first conveyance port, 13--111it feed roller, 14-pressure roller, 19-mylar film, 20-pressure release solenoid, 22-pressure roller arm, 23- opening, 24-pressure solenoid, 27-torsion coil spring, 29.30-folding roller.

Claims (2)

[Claims] (1) A pair of folding rollers that pinch and crease the sheet material; A conveyance path having an opening at the portion of the pair of folding rollers; A conveyance path located upstream of the pair of folding rollers on the conveyance path and does not restrain the sheet material. a variable conveyance means that can take a release state, a weak conveyance state in which a weak force is applied to the sheet material, and a strong conveyance state in which a strong force is applied to the sheet material; A sheet skew correction device comprising: a stopper portion located on the downstream side; (2) The sheet skew correction device according to claim 1, wherein the variable conveyance means is a pair of rotating bodies that can move toward and away from each other and have variable contact pressure.